Burglar alarm



Dec- 4 1923' r k w. T. KJELLAND BURGLA ALARM Filed June 4. 1923 3Sheets-Show; 1

mm 1 L Dec.- 4 1923.

w. T. KJELLAND BURGLAR ALARM 3 Sheets-Sheet 2 F ed June 4. 1925IV/T/VES5ES Dec. 4, 1923. 1,476,340

, w. T. KJELLAND 'BURGLAR ALARM Filed June 4. 1925 Y s Sheets-Sheet aPatented Dec. 4-, 1923.

UNITED STATES WILLIAM 'r. KJELLAND, or SNOHOMISH, wAsHiivGToN;

BURGLAR ALARM.

Application filed June 4, 1323.

To all whom it may concern:

Be it known that I, VVILLIAM T. KJEL- LAND, a citizen of the UnitedStates, residing at Snohomish, in the county of Snohomish and State ofWashington, have invented certainnew and useful Improvements in aBurglar Alarm, of which the following is a specification.

I This invention relates to alarms or signals and'more particularly todevices for giving an alarm or signal, when unauthorized persons attemptto gain access into a room or house and is an improvement over my priorPatent #1.,257,881 issued to me February 26, 1918.

The primary object of the present invention is to provide an improvedmeans for quickly and readily placing the improved burglar alarm on adoor knob, and novel means for holding the body plate of the alarm fromagainst swinging movement, when the door knob is turned by unauthorizedpersons.

Another prime object of the invention is to provide an improved meansfor constructing the novel alarm, whereby a relative great leverage isobtained for actuating the trip, for setting the alarm bell inoperation.

A further prime object of the invention is to provide an improved meansfor setting oh the alarm and improved means for permitting the alarm toactuate continuously after being operated or for operating only a shortlength of time or during the turning movement of the door knob.

A still further object of the invention is to provide an improvedburglar alarm for hotel rooms or the like of the above charac ter, whichwill be durable and efficient in use, one will be simple and easy tomanufacture, and one which can be placed upon the market at a reasonablecost.

With these and other objects in view the invention consists in the novelconstruction,

." arrangement and formation of parts, as will be hereinafter morespecifically described, claimed and illustrated in the accompanyingdrawings, in which drawings:

Figure 1 is a perspective view or the improved burglar alarm, showingthe same applied to a'door, the door knob spindle being shown insection.

Figure 2 is a detail section taken on the line 2-2 of Figure 1, showingthe improved alarm in transverse section.

Serial No. 643,428.

Figure 3 is a longitudinal section through the improved alarm showingthe same apphed to a door, the door being also shown in sectlon.

Figure 4 is a front elevation of the improved alarm showing the sameapplied to a door, the door knob spindle being shown in section,- thecover of the alarm being shown removed.

Figure 5 is an enlarged front elevation oi the lower end of the alarm,showing the cover and frame plate of the alarm removed therefrom. I

Figure 6 is a detail transverse section taken on the line 6-43 of Figure5 through the alarm. j

Figure 7 is a detail section taken on the line 7-7 of Figure 4 throughthe clamping means utilized for holding the alarm on the door knob.

Figure 8 is adetail perspective view of the stop plate for limiting theringing of the alarm.

Figure'9 is a detail perspective view of the means utilized foroperating the same stop. 7 1

Referring to the drawings in detail, wherein similar referencecharacters designatecorresponding parts throughout the several views,the letter A generally indicates the improved burglar alarm, whichconsists of the door knob shank engaging clamp B, the base plate Cconnected with said clamp, the alarm device per se- D, and the means Efor operating the alarm D fromthe door knob shank engaging clamp B.

The door knob shank engaging clamp B comprises a pair of movable arms 10and 11, which are connected together, at their outer ends by means of apivot pin 12. It is preferred to make the arms 10 and 11 out of sheetmetal and construct the same U-shaped in cross section to add to therigidity thereof. The opposite ends of the arms 10 and 11 from the pivotpin 12 terminate in clamping jaws 14 which have inner active faces ofV-shape for engaging the shank of a door knob. These jaws l l areadjustable toward and away from each other for engaging the door knobshank, by means of an adjustable thumb screw 16, which extends throughthe arm 10 and into a threaded nut 17 hingedly carried by the arm 11.

The base plate G is of a substantially triangular configuration anddepends from the arm 11 at a point directly below the centers of thejaws 14 and the plate is connected with the jaw of the arm 11, by meansof a pivot pin or the like 18, which permits free swinging movement ofthe plate C in relation to the clamping member B.

It is of course, to be understood, that the alarm is particularlyadapted to be placed on the inside of doors of hotel rooms and the likeand thus the alarm device is to be considered as of portable nature.

In order to clearly illustrate the operation of the alarm, the same isshown in connection with an ordinary type of door l having the usualdoor knob shank G to which is secured the door knobs H. The base plate Ccan be provided with a longitudinal .y extending slot 20, which isadapted to align with the key-hole in the lock and thus persons lookingthrough the key-hole from the outside of the door will not be able tosee the alarm device and the slot 20 permits the insertion of the keyinto the key-hole through the said plate C. This key will prevent theswinging of the plate C and thus permit the positive operation of thealarm device per se.

The lower end of the base plate 0 has rigidly connected thereto in anypreferred way, the alarm device per se D, which includes a bell of theusual type embodying a spring for operating the bell clapper. As shown,the clapper is indicated by the reference character 21 and is adapted tooper ate against the rotatable cover or hell 22,

which is utilized for rotating the shaft 23 for winding up the spring.The shaft 23 operates through a train of gearing 24 and an escapementmember 25, which carries the bell clapper 21. The specific constructionof the hell does not enter into my invention. One end of the clapper 21opposite to the es capement member 25 is provided with an extending ear26 and a stop member 27 embodying an outstanding ear 28 is arranged forengaging the ear 26 of the clapper so as to prevent the normal operationthereof. This stop embodies a flat plate 29 having a slot 30 forreceiving the shaft 23. A tongue 31 is turned back from the plate forreceiving an operatingrod 32, for governing the movement of the saidstop 27, as will be hereinafter more fully described. An elongated slot33 is provided in the plate 29 through which passes a post 34 of theframe of the alarm device per se D and on this post 34 is rotatablymounted the release or trip member 35. This release or trip member 35embodies an outwardly extending arm 36, and a T-shaped head 37 which isadapted to normally engage parallel disposed upstandinglugs 38 formed onthe plate 28.

The means E for operating the alarm device per se D consists of a rod40, which is detachably connected to the arm 11 of the clamp device Badjacent to the outer end thereof and the lower end of this rod isprovided with a hook 41, which extends through an eye 42 formed in thearm 36.

It is obvious that when the door knob is turned, that the clamp member Bwill be turned therewith, which will swing the release member 35 throughthe medium of the operating device E. This will operate the stop member2'7 in such a manner as to move the ear 28 from out of the path of theear 26 formed on the clapper 21, which will permit the operation of theclapper through the train of gearing 24 and the escapement member 25. V

The plate 0 is prevented from swinging movement owing to the faot thatthe key extending through the slot 20 thereof will hold the plateagainst movement.

A swinging lever 45 is extended into the bell and is rotatably mountedupon a post 46 and this lever 45 has connected thereto the rod 32 andthus it is obvious that when the lever is swung outward, that the plateor stop 27 will be rotated causing the ear 28 to again move in the pathof the ear 26 formed on the clapper 21. The outer end of this lever isprovided with operating thumb teeth 47, and a dog or tooth 48 forengaging in a rack bar 50 struck out from the plate C. By means of thislever 45the alarm can be set to ring a short time or for a long lengthof time. Thus when the lever 45 is swung to the right, this willincrease the tension of the rod 32 which is of resilient material on theear 31 and when the plate 28 is operated by the release trigger or trip35, tension on the said trigger or trip 35 is released, the tension ofthe rod will throw the plate 28 back to its normal position so as toprevent further operation of the bell clapper.

When the lever 45 is swung to the left, it can be seen that the tensionon the rod 32 is decreased, which will permit the continuous operationof the clapper 21 when the trip or trigger 35 is operated.

The alarm is usually held on the door by the door key, but when the keyis removed, the supporting rod can be utilized for holding the alarm inplace. This rod 60 has one terminal thereof terminating in a sharppointed prong 61 which can be forced between the door and jam, asclearly shown in Figure 1. WVhen the alarm A is left on the door, thealarm can be set so as not to sound by turning the rod 60 around, sothat the prong 61 will extend outwardly from the door and inserting aholding screw 63 in an eye 62 formed on the rod. After which the arms 10and 11 are slightly released by loosening the set screw 16 and byswinging the lever to the right.

By tightening the screw 16 again the alarm is set for short rings. Ifdesired a spring 11 can be disposed between the arms Eli) 10 and 11 fornormally holding the arms apart. The plate C carries a resilient tongue64 which is adapted to engage in rear of the rod and thus hold the plateG in position and against movement. It is of course obvious, that thealarm can be readily removed when so desired, such as during daytime bysimply unloosening the clamp member D and raising up on the plate (3,which will permit the spring tongue 64 to release therod 60.

From the foregoing description, it can be seen that an improved burglaralarm has been provided of exceptionally durable con struction, whichwill permit the positive operation oi the alarm upon the turning of thedoor knob and permit the alarm to be either rung continuously or for ashort duration of time. I

lVhat I claim as new is 1. In a burglar alarm for door knob spindlescomprising an adjustable clamp for engaging the spindles, a dependingplate pivotally associated with the clamping memher, an alarm bellassociated with the lower end of the plate, means for operating the bellincluding a pivoted trip member, means connecting the trip member withthe outer end of the clamp member, and means for permitting the bell toring continuously or for a short duration of time after being operated,said means including a spring rod and an adjusting lever for said springrod.

2. A burglar alarm operated from door knob spindles comprising anadjustable clamp for engaging the door knob spindle, a pendant platesecured to the clamp, a signalling device secured to the lower end oithe plate, a trip member for operating the signalling device, a rodoperatively connecting the trip member with the clamping device,resilient means for normally holding the trip device in an operativeposition, and adjustable means for rendering the resilient meansinoperative.

3. In a burglar alarm adapted to be operated from a door knob spindle, aclamping device for engaging the door knob spindle, a pendant platepivotally secured to the clamping member, a signalling device carried bythe lower end of the plate, means for operatin the signalling member, arod connecting the operating means with the clamping member, asupporting rod for connection with a door, a resilient tongue carried bythe plate for engaging said rod.

4;. A burglar alarm comprising a relatively fixed plate, an attachingmember for engaging a door knob to be turned thereby, an alarm apparatussecured to said fixed member including tripping means to set the same inoperation, a rod connected with said tripping means and to saidattaching member, a tensioning member for causing the return of the tripmember after operation When so desired, and means for adjusting saidtensioning member.

5. A burglar alarm comprising a fixed member, a clamping member forengaging a door knob to be turned thereby, an alarm bell carried by thelower end of the fixed member and including a vibrating clapper, anupstanding ear formed on the vibrating clapper, tripping means for thebell including a connecting member connected withthe 75 attachingmember, a trip plate operated by said trip member including an ear forengaging the ear on the clapper, a resilient rod engaging said tripplate for normally holding the ear formed thereon in the path of theclapper, a pivoted lever carrying said trip member, and means forholding the lever in different positions on the fixed member.

In testimony whereof I afiix my signature in presence of two witnesses.

l/VILLIAM "T. KJELLAND.

Witnesses Gno. T. HnNDRIo, A. R. SLUYSTER.

